A call data record (CDR) is a data record produced by communications equipment that documents the details of a call or other communications transaction passing through the equipment. The record contains attributes of the call, such as time, duration, call quality, call statistics, completion status, originating point, and destination point. CDRs are used by VoIP service providers to analyze and monitor call quality and statistics, and to take service assurance measures.
To create a CDR for a given call, a VoIP service provider must rely on the unique internet protocol (IP) address of the end point to uniquely identify the customer, and his/her location. With the shortage of IPv4 public addresses for end devices, the service provider is now moving away from fixed IP addresses, instead using dynamic IP address assignment for each VoIP call session. One challenge of that new approach is identifying the customer's calling or called site/location when each VoIP call has changing and dynamic IP addresses at the source and the destination.
One approach used by VoIP service providers is to capture the telephone number assigned to each customer end device and use that number as a search key to identify the associated customer site ID. For business call services, however, many intra-office calls at the local branch use 4-digit or 6-digit local numbers for direct dialing. The 4-digit or 6-digit direct dialing numbers captured in the resulting CDR are unique only at the local branch, and not across branches or companies. As a result, using telephone numbers captured in the CDR requires extra logic to uniquely identify calling and called parties and associated customer site IDs in a business service call with direct dialing features.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.